In the use of a lubricating system for an engine, it is desirable to maintain an uninterrupted flow of lubricant to the piston crown, connecting rod bearings and adjacent crankshaft journals and to maximize surface areas of the bearing and connecting rod in the areas of principal loading of the bearing.
U.S. Pat. No. 3,069,926 which issued to Hoffman et al on Dec. 25, 1962, shows a passage in a crankshaft and first and second notch defined openings or passages in a bearing. A groove in a principal loading area of the bearing is positionable in fluid communication with the journal passage through the notches to receive fluid for lubricating the bearing. U.S. Pat. No. 2,131,170 which issued to Evans on Sept. 27, 1938, shows a similar engine lubrication system. U.S. Pat. No. 2,199,699, which issued to Frelin on May 7, 1940, shows yet another such lubrication system which provides continuous flow to the bearing through two passages in the journal which are oriented at right angles one to the other.
U.S. Pat. No. 2,916,333 which issued to Johnson on Dec. 8, 1959, discloses a journal passage positionable in fluid communication with first and second passages defined by a bearing and the journal only at intervals during rotation of the journal. U.S. Pat. No. 2,940,802 which issued to Love on June 14, 1960, U.S. Pat. No. 3,495,685 which issued to Rivaum on Feb. 17, 1970, and U.S. Pat. No. 3,625,580 which issued to DeHart on Dec. 7, 1971, disclose similar embodiments of engine lubrication systems.
In an engine, a connecting rod is connected to a rotatable crankshaft journal and a bearing connected to the connecting rod is positioned between said rod and the journal. A lubricating film is provided between the interacting bearing and journal to provide a lubricated cushion for the connecting rod and to prevent failure of the bearing. Piston crown areas and pins connecting the pistons to the connecting rod are also lubricated through connecting rod passages to increase engine durability. Lubricant for such purposes is commonly supplied through a passage in the crankshaft journal to passages defined by the bearing and journal. Said crankshaft journal passage is positionable in fluid communication with the bearing and journal defined passages in response to rotation of the crankshaft journal. In this manner, lubricant is supplied from the journal passage to the bearing and journal defined passages for lubrication of the engine, as mentioned above.
Heretofore, establishing continuous flow of lubricant from the journal passage to the bearing and journal defined passages was commonly accomplished through the use of such bearing and journal defined passages positioned in principal loading areas of the bearing. This provided continuous fluid communication between the journal passages and bearing and journal defined passages. However, the resultant reduction of surface area in the bearing and/or adjacent surface of the connecting rod reduces load carrying capacity of the bearings. This can sometimes result in early failure of the bearing and shut-off of lubrication to the piston.
In removing the passages from the principal loading areas of the bearing, the journal passage has been most commonly positionable in fluid communication with the bearing and journal defined passages only during intervals in the rotation of the crankshaft journal. The result is an intermittent flow of lubricant from the journal passage to the engine, reducing the lubricating and cooling efficiency of the lubricating system. Where the passages are in continuous fluid communication with the journal passages, such passages encroach into less, but still highly loaded, portions of the bearing. Thus, bearing surface is not maximized in order to carry the tremendous loads encountered in the engine.
The present invention is directed to overcoming one of more of the problems set forth above.